Device on automotive vehicles for preventing the inadvertent backward motion of the vehicle



4 Sheets-Sheet L W. HUSY INADVERTENT BACKWARD MOTION OF THE VEHICLE DEVICE ON AUTOMOTIVE VEHICLES FOR PREVENTING THE ell/4:70

Nov. 7, 1950 Filed Feb. 25, 1948 Nov. 7, 1950 w. HUSY 2,528,957

- DEVICE 0N AUTOMOTIVE VEHICLES FOR PREVENTING THE INADVERTENT BACKWARD MOTION OF THE mucus Filed Feb. 25, 1948 4 Sheets-Sheet 2 lllzilll' Jig? Nov. 7, 1950 w. HUSY 7 DEVICE on AUTOMOTIVE VEHICLES FOR PREVENTING THE INADVERTENT BACKWARD uo'non on THE VEHICLE Filed Feb. 25, 1948 4 Sheets-Sheet s l .r /l/ 1E 33 O Z 50 Nov. 7, 1950 w. us 2,528,957

7 DEVICE 0N AUTOMOTIVE VEHICLES FOR PREVENTING THE INADVERTENT BACKWARD MOTION OF THE VEHICLE Filed Feb. -25, 1948 4 Sheets-Sheet 4 WM "MM/M435 Patented Nov. 7,

L UNITED-- STATES PATENT -OF FKIE we e v 2528,95,; Z

DEVICE ON AUTOMOTIVE vEHI'cLE's FOR 7 PREVENTING THE INADVER'IENT BACKa WAR MOTION 'OF THE VEHICLE W alter Busy, Zurioh,'-"Switzerland Application February 25, 19 1s, .Serial N0..10,836 I In Switzerland July .3, 1946 M present inventio'nrelates to a device on automotive vehicles for preventing the 'inadvertent backward motion-of the vehicle.

Quite a number of device on automotive vehicles have been-suggested which are intended to prevent a backward motion of the vehicle which may easily occur when starting uphill. With the conventional automobile this backward motion must be preventedby 'thedriver by use of the hand brake which necessitates the skilful manipulation of hand brake, clutch and throttle lever and may in addition cause dam-;

age to the mechanism of the vehicle by stalling the'engine as well as by collisions with other road users. Some of the devices suggested are 4 Claims. (01. 192---1) or the type'with a'pawl and ratchet mechanism,

others are a special design of the free-wheel. Pawl and ratchet'locks are not only complicated and unwieldy structure because of their multiplicity of parts for which reason alone they are not suitable for automotive vehicles and in particularthoseused. for the conveyance of passengers, but they are also unfavorable with regard to the required possibility of releasing the locked 'reverse'as is necessary when the vehicle is-to be reversed intentionally as for example when manoeuvring etc., and they can be ineffective in the no-load condition'only. In common with the aforementioned devices the freewheel constructions also have as their weak point the controlling of the wedging bodies to enable intentional reversing, and in'this case too this manipulation-can only be carried out when the device is not loaded.

The present invention aims at eliminating the drawbacks described, and it-coneerns a device in automotive vehicles for preventing the unintentional backward motion of the vehicle in which a lock'islocate'd in the train of the transmission from the engine to the driving wheels which permits "the reverse gear to be engaged directly without'first having to relieve the trans mission of the driving load.

The accompanying drawings illustrate "schematically various possible embodiments of the invention, whereby only the parts are shown which are necessary forthe understanding of the invention, and in which v Fig. 1 is an endview of a first'example, and

"Fig'Zbeinga'pIan'vieW thereof;

'Fig. 3Iis a-detail of'the operating-mechanism of=an embodiment in one position, and

Fig.4 the same detail in another position;

Fig. '5 is an alternative of the detail accordingto Figs.3'and'4.

:2 o Fig. 6 showsan end view of a second-embodiment of the'invention, Fig."7'being a plan viewthereof, Fig. 8 illustrates in section an alternative detail of the operating-mechanism. *Fig. '9 isan end'vi'ew of a second embodiment to which thealternative detail according to Fig. 6 belongs. Y Fig. 10 'is'a plan'view of this-embodimenh-and Fig. 11 represents a further detailed alternative ofthe' operatingmechani-sm.

According to the-first form of embodiment ofthe'invention l is the shaft of ach'a-nge speed gearof an automotive "vehicle-e; g., an automobile used for the conveyance-of passengers. On this shaft l theinner part 2 of a locking-de vice representing thereverse lock is 'keyed. This inner'p'art '2 is surrounded by an-outer =part 3 of the -lockin -device representing a roller ring mounted-on balls Between parts =2 and 3 chambers "5 circumferentially spaced are formed representing wedging surfaces between the walls of parts Z-a'n'd Svvhereby the'inner'wail-of part' 3 is circular whilepar-t-l? has flat surfaces extending tangentially. Ineach of the'chambers 5 there is a roller 6.

The roller ring 3 'has dogs I on it -outer surface which are e'ven'ly spaced on the circumfe-r ence-ofthe ring and cooperate with a"1ocking dog 3. llhe locking-dog'li is subjected to the ac tion of a pressure sprin Q, whichbear's-on said dog and the wall of 'a housing [fi -surrounding the locking device, and is pivoted to a lever *ll which is'=rota-tably mounted -'on the floor *of the housing It. The lever-H extends with acleara ance betweenthe stops W2, 43 which aremounted on'a push rod l4, and'-it has a shoulder '15? In-theho1ising l-fl a-bell crank lfiyi'lls pivotally mounted whose arm It cooperates with stop 1- 2 of the push rod and whose arm ll cooperates with--s'houlder1 5 -of lever 14, and this bell-crank forms a' lock for the "locking dog 8 in one *of the dogs of rtherolle'r ring. r

' 'The' memos is pivoted to the end-of arm lfl 'f-a'bell crank t-8, 49 and' its 'head fifi formed-= eitthispivot-cooperateswith a cam'-2-l of the shift rod 22 of the reverse gear of the change speedgear-of 'an automobile {The arm I 9 'ofbell crank' l8'j H3 cooperates with-shoulder -23 of a;- lever 24 which is pivoted to the housing It! at 25 and presseswith one end '2 T against a' second cam T28 'of; the shift 'ro'd 22under theiaction of a WHeh the 'reverse' gear is' not in a ction the parts described are -intlr'e position shown in-Figs."

1 and 2, i. e. the shift rod I 4 is located to the right and its head 20 rests at the bottom of cam 2|. The locking dog 8 meshes under pressure of spring 9 between two dogs 1 of the roller ring 3, thus locking the latter against rotation, and the bell crank l6, l1 locks the lever H in the locking position of the dog 8 by means of the arm I! and the shoulder l thus securing the locking of the roller ring 3. The arm 19 representing together with shoulder 23 and lever 24 a locking arrangement is out of engagement with shoulder 23, and the end 21 of lever 24 rests against the bottom of cam 28.

In this position of the various parts the rollers 6 are free to rotate in the chambers 5 when the vehicle moves in a forward direction whereby the inner part 2 of the locking device rotating together with shaft l in the direction of arrow 29 moves the rollers 6 towards the sections of the chambers 5 where the walls of 2 and 3 are a greater distance apart than is represented by the diameter of the rollers 6. Should the vehicle tend to roll backwards the rollers 6 in the chambers 5 are rolled into the narrowing of the wedging surfaces formed by bounding walls of 2 and 3 by thereversal of the direction of rotation of shaft l and are wedged there securely engaging shaft I with the roller ring 3 to form a solid whole to prevent the backward motion of the vehicle. 7

If it is desired to drive backwards intentionally i. e. if the reverse gear of the motor car is engaged, then the shift rod 22 being shifted in the direction of the arrow (Fig. 2) moves the push rod [4 to the left by the shifting action Of the cam 2| on its head 20. Thereby, in the first place, the stop 12 comes up against the arm l5 of the bell crank I6, I! to lift arm I! out of the way of shoulder I5 thus releasing the lock of locking dog 8. Then stop l3 comes up againstlever II and moves it against the pressure of spring 9 thus pushing locking dog 3 out of engagement with the dogs 1 and allowing roller ring 3 to rotate freely, i. e. the outer part of the locking device together with its inner part, in the opposite direction to arrow 29. V

. In moving push rod [4 to the left arm 19 comes to lie on shoulder 23 by the spring urged movement of lever 24 and is locked in that position inasmuch as the operation of engaging the reverse gear has no effect on this lever 24.

As long as the reverse gear is engaged this look at I9, 23 remains effective and with it the possibility of reversing the motor car. When disengaging the reverse gear this lock remains effective until, after the gear wheels of this gear have come out of mesh, the end 21 of lever 24 rises slightly on the cam path 28 in the last phase of the movement of shift rod 28. By this means lever 24 is pivoted against the pressure of spring 26 and shoulder 23 is lifted off arm I9, 1. e. the lock of locking dog 8 in the position in which it has not effect of roller ring 3 is eliminated and push rod I4 as Well as lever .II with looking dog 8 return to their original position and locking dog 8 again comes into engagement between two dogs 1 of roller ring 3 thus looking it again. This lock in its turn is again secured in its original position by the locking bell crank When engaging the forward gear associated with the reverse gear the shift rod 22 has to be given a slight backward movement in the direction of arrow 30 after completing the disengagingmovement sothat shoulder moves into;

car which may'take the form of a colored signal- 7 ing lamp. In the current circuit of this lamp there might be a contact the blade 3] of which projects into the path of motion of a third arm 32 on locking lever l6, 11. If the lock formed by the locking elements 2, 3 is in action the .arm 32 is out of reach of contact arm.-3l and the switch is open and therefore the lamp switched off. If, however, the lock is made inoperative arm 32 presses on contact 31 through the pivoting motion of bell crank l6, ll caused by stop l2 and closes the switch of the lamp thus causing it to light up. a

In addition provision can be made'that the locking device can be cut out by the driverwat his free will and independently of the engagement of the reverse gear of the motor car. For this purpose a cable pull 33 engaging push. rod

I4 may be provided to the other end of which is attached an operatingmeans located onthe instrument panel '34 or the steering column.

Figs. 3 and 4'show such an operating means. In a cylinderfil a movable plunger structure is slidably arranged the extension of which ends in a handgrip 64 protruding through the instrument panel 34. To the other end the draw cable.

33 is attached. 'Inside of this part a rod 65 is.

fitted which ends in a push button 66 projecting out of the handgrip 64.- Halfway along this rod there is a taper-shaped enlargement 61 as a lock- By pressing in the push button 66 the spacingpiece 61 is displaced sufficiently to allow the roller members to drop out of the recesses 10; then the plunger structure on hand-grip 64 can be shifted to the next notch into which the roller. members areguided by the pressure caused by,

the wedge action of the spacing piece 61. Fig. 4 shows the cable pull in the drawnposition.

In place of the cable pull fixed to the instru-"-; ment panel (according to Figs. 3 and 4) the draw; cable 33:;may be operated a lever mounted pivotally to the steering column, asshown in Fig; 5

and arranged as follows: To the steering column 8| a plate 82 is afiixed in which a shaft 83 is pivotally mounted. On the upper end of this;

shaft there is a lever 84 with grip 85. lower end of shaft 83, which extendsdownward to the fioor-boardofthe "vehicle there is a-lever 86 to which thecable pull 33 is attached; In: addition of plate 81 having, a spring actionis' securely pinned to the top end of-shaft 83and in this plate a -stud 88v is inserted In plate 82 two openings 89 and BDare provided which serve as notches forstud. 88.; In the lever position according to notch 89 the-locking device is engaged, and in the the position 90 it is disengaged.

Instead-of operating the locking device mechanically as described it m lll also bedone by.

pressuremeans. Such an embodiment is shown inFigs. 6-10. v

In this case the shift rod 22 (Fig. 8) is linked to: piston 41 of a cylinder space48 by means of a lever 46 and this cylinder space is connected through a valve 49-to a pipe line 50 said pipeline leading to a cylinder space 5| on the locking device. In this second cylinder space- 5| a piston 52 is displaceably provided said'piston being connected to push rod l4 through a lever 54 pivotally mounted in housing in at 53. Value 49 is pressed against a cam 56 on the shift rod 22 with ahead 69a, by means of a spring 55.

If. the reverse gear is engaged, i. e. if the shift rod 22 is pushed to the left from its normal psi.- tion 0 (Fig. 8), lever 45 moves piston 61 to. the right in the cylinder space 48-, i. e. the cylinder space-48 is reduced and some of the pressure means, which may be oil, is displaced through valve 48 and pipe line iiz-into the cylinder space; 54. moved outwardly in this cylinder space and it pushes the push rod M to theleft causing an abutment piece 5? ofthis push rod M to disengage bell crank lfi, ll from shoulder l5 and the lever l! to withdraw the locking dog 8 from the'roller ring 3.

The-amount of oil displaced by this movement.

is so chosen that on completion of the engagement of the reverse gear the locking dog 8 is fully Withdrawn, and that in addition a spring 58 back of a piston 59 in a cylinder space 60.

communica-ting'with pipe line 50 has received a certain tension to act as an elastic intermediary means. Valve ie prevents the reflux of the oil beingreleased by cam 56 on engaging the reverse gear and being closed by spring 55 (shown by dotted lines in Fig. 8). On disengaging reverse gear valve 69 is again opened by cam 55 so that by means of spring 9 the former pressure condition is again restored and the back motion looking, device comes into action again.

In this case too the putting out of operation of the locking device from the drivers seat of vehicle can be applied by means of a cable pull 33- whereby, as shown in Fig. 6-, the cable pull 33 is attached to push rod M at thev abutment 51 and a Sliding sleeve 5! is inserted in the push rod It which sleeve allows the push rod M to be drawn out by cable pull 33 without affecting the pressure side.

As shown in Fig. 11 the cable pull 33 might act directly on the pressure means by acting through a lever 62 on a piston 63 in a cylinder space 64 connected to the pipe line 50 leading to the operating piston of the locking dog. Here too a damping piston 59 could be provided.

The safety means against a premature engagement of the locking dog with the dog-toothed rim is provided by the special shaping of the dogs inasmuch as their unilateral superelevation prevents the locking dog from coming into engagement as long as the dog-toothed ring is moving (reverse driving direction). The root of the dog teeth as well as the tip of the dog teeth can have unequal heights of the flanks. Due to this safety means a premature engagement of the locking dog with the gear shaft is impossible and therefore damage to the power transmission elements is eliminated with certainty. On the other hand the same superelevation has the effect that when driving ahead the engagement is brought about automatically by the locking dog knocking against the dogs of the ring. Because of the exactly determined difference of height of the flanks the Thereby piston 52 in this cylinder space is.

function is also assuredthat the engagement of the locking dog, with the dog-toothed ring takes place at the moment the vehicle. comes to. rest.

, Concerning the certainty of the engagementofi I thelocking dogwith the dog-toothed ring thisiis assured by the correct functioning of the; bell crank it, H.

I-he inner part of the locking element forming the locking. device can have the walls forming part of the chambers variously shaped to: form the complete chambers. Thus the; front partsof the walling can have a wedge-shaped overlap which'causeid alifting-off of the rollers E from. the outer. locking element, the roller ring whenever therollers are being pushed; The wedging sur faces can also have a curved shape. Instead of being fitted to agear box of an automobile the locking device could also be located insome other position in-the train of the drive-from the'engine tothe driving wheels of the vehicle as for-example near the differential gear in which case it might be built together with thehousing of the differential gear.

The device according to the invention allows" above all to make the locking device inoperative without having to relieve it or" its lead preliminarily. This not only simplifies the manipulation of the device but it also gives a great oertainty in traffic as well as in the action of the device and in addition its parts are not subjected tobreakage and wear andtear. Furthermore the locking means in the locking device act equally concentrically thus no one-sided radially acting, shockstresses can occur.

What, I claim and desire to secure by Letters Patent is:

' l. A device for preventing unintentional back- Ward motion of a, vehicle comprising a locking devicearranged in the transmission of the vehicle and comprising an inner member rigidly fixedto a drive shaft in said transmission, a roller ring rotatably mounted around said inner meme. her having an inner circular wall said inner, member having irregular shaped teeth thereon and forming with said inner circular wall of said. ring a plurality of circumferentially spacedi wedge shaped spaces, a roller in each said space, each said space varying in width from substantially zero to a width greater than the diameter of said rollers, a plurality of teeth in the outer surface of said roller ring, a spring pressed locking dog for engagement with said teeth on said roller ring and normally locking said roller ring from rotation, release means for said dog operatively connected to a gear shaft mechanism of said transmission and operating to release said dog when the transmission is placed in a reverse position, said inner member being free to rotate in said roller ring in one direction of travel of the vehicle when said dog is engaged but being braked by said rollers acting in said wedge shaped spaces when said vehicle travels in the opposite direction, said roller ring being free to rotate with said inner member when said dog is released by said release means upon reversing said transmission, latching means for said dog comprising a lever rotatably mounted and connected to said dog, an abutment on said lever, a pivotally mounted bell crank having an arm thereof for engagement with said abutment, a push rod having two stops thereon, said lever extending between said two stops, 9, second arm on said bell-crank being actuatable by one said stop to release said first arm from said abutment and said lever being movable by the other of said stops to release said dog from said roller ring.

2. A device as claimed in claim 1', a double surface cam secured to the reverse shift rod of said transmission, a lever having a shoulder thereon pivotally mounted in the housing of said device, an end of said lever pressing against one said cam surface, the opposite end of said lever being spring connected to said device, a second bell crank pivotally mounted, an end of said push rod being pivotally connected to the end of an arm of said second bell crank, the said end of said push rod contacting a second of said cam surfaces, a second of said arms of said second bell crank cooperating with said shoulder on said lever, said shoulder and the bell crank arm cooperating therewith constituting a lock for holding said push rod in a position to disengage said dog from said roller ring when the transmission is in reverse position, said cam surfaces actuating said push rod when said shift rod is moved in one direction, and said lever to disengage said shoulder and said crank when moved in an opposite direction.

3. A device as claimed in claim 2, said means comprising a cable pull, said cable pull being connected to said push rod for actuation thereof to disengage said dog from said roller ring, wedging means for holding said cable in a predetermined position, and means for releasing said wedging means.

4. A device for preventing unintentional backward motion of a vehicle comprising a locking device arranged in the transmission of the vehicle and comprising an inner member rigidly fixed to a drive shaft in said transmission, a roller ring rotatably mounted around said inner member having an inner circular wall said inner member having irregular shaped teeth thereon 8 roller ring-and normally locking said roller ring from rotation, release means for said dog operatively connected to a gear shaft mechanism of said transmission and operating to release said dog when the transmission is placed in a reverse position, said inner member being free to rotate in said roller ring in one direction of travel of the vehicle when said dog is engaged but being braked by said rollers acting in said wedge shaped spaces when said vehicle travels in the opposite direction, said roller ring being free to rotate with said inner member when said dog is released by said release means upon reversing said transmission, said means for releasing said dog from said roller ring comprising a push rod, a lever operatively connected to said dog, said push rod being operatively connected to said lever for moving the same, a first cylinder, a piston displaceable therein, means connected to gear shift means for said transmis-' sion to move said piston in said cylinder, a second cylinder in said device, a pipe connecting both said cylinders; a piston in said second cylinder, a lever 'pivotally mounted in said device at one end thereof, said piston in said second cylinder being connected to said lever, the free end of said lever being connected to said push rod whereby upon actuation of said gear shift mechanism said push rod will be actuated to release said dog from said roller ring by transfer of pressure from said first cylinder to said second cylinder.

WALTER HUSY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

